Development of RNA pol‐driven adenovirus vector expressing hepatitis C virus replicon

Abstract

An estimated 170 million people are infected with hepatitis C virus (HCV), which leads to chronic hepatic inflammation, hepatic fibrosis and hepatocellular carcinoma. Development of potent therapeutic strategies is critical for overcoming HCV, and efficient delivery of an HCV RNA replicon into cells is useful for basic and pharmaceutical studies. However, conventional assay systems for HCV infection have not been fully developed. Adenovirus (Ad) vectors have been widely used to deliver foreign genes to a variety of cell types and tissues in vitro and in vivo, as they are simple to prepare, grow to a high titer, and use for efficient transfer of genes into dividing and non‐dividing cells. However, Ad vector‐mediated assay systems for HCV replication have not been developed. In the present study, we developed an Ad vector containing an RNA pol‐dependent expression cassette and a tetracycline‐controllable RNA pol I‐dependent expression system. We prepared a hybrid promoter from the tetracycline‐responsive element and the RNA pol I promoter. Ad vector particles coding the hybrid promoter driven HCV replicon were prepared, and HCV RNA pol‐dependent HCV replication was confirmed in the cells transduced with the Ad vector coding HCV replicon. An inhibitor of HCV replication reduced HCV replication in the Ad vector‐transfected cells. To our knowledge, this is the first report on the development of an Ad vector‐mediated HCV replicon system.